This invention relates to a method for recognizing a machine encoded character font and more particularly to an accurate character finding and recognition algorithm for a more reliable optical character recognition method.
For documents which can frequently be found to have within a scan band, backgrounds, teller bank stamps, or customer signatures, optical character recognition of a machine encoded character font is difficult. When no optical clear band exists, backgrounds, signatures, etc. can be interpreted as characters thereby leading to rejected, misread (substituted), or extra (a blank location interpreted as data) characters.
Optical character recognition of a machine encoded character font, such as the E13B Magnetic Ink Character Recognition (MICR) font, is a difficult process as no optical standard exists for this font because the E13B characters were originally designed for magnetic reading and recognition. Because of the lack of an Optical Character Recognition (OCR) standard, foreign signals such as customers' signatures, bank teller stamps, scenic check backgrounds, etc., can be overlayed on top of the E13B MICR characters. These foreign signals will also be lifted optically together with the E13B MICR characters resulting in increased character rejects and misreads. Precise location of the E13B MICR characters within the scan band is a difficult but very important task for any optical character recognition scheme. Characters not precisely located can be rejected or misread due to the increased background noise of the optical E13B scan band.
Previous optical character recognition methods utilize a single pass character location and recognition approach. This has the disadvantage in that any MICR character would have to be precisely located by a fairly sophisticated and accurate character finding and recognition algorithm. The present invention is an optical character recognition technique devised to recognize E13B font MICR characters. The optical character recognition technique of the present invention utilizes a two pass operation wherein the MICR scan band image is processed two times. The two passes utilized by the present invention for the optical location and recognition of the E13B font character results in a reliable recognition of the E13B characters in an optically contaminated scan band.